An aggregation-induced emission (AIE) based smart singlet oxygen (1O2) generation system has been successfully fabricated based on supramolecular host–guest assembly. The controllable 1O2 generation can be achieved by conveniently changing the molar ratio between the macrocyclic host (WP5) and the guest molecule (TPEPY). Moreover, reversible control of 1O2 generation and fluorescence emission of supramolecular nanoassemblies can be achieved VIA adding Fe3+ and EDTA, which allows qualitatively monitoring the singlet oxygen generation efficiency by the naked eye.